With the continuous development of the display technology, more and more display devices adopt a GOA (Gate on Array) technology, that is, a gate driving circuit is formed on an array substrate of a display device by an array process. The GOA technology can save costs and achieve symmetrical attractive design on both sides of the display panel, and the bonding area of the gate driving circuit and the fan-out wiring space can be simultaneously omitted, so that the design of narrow bezel can be realized. In addition, the GOA technology can also save the bonding process in the gate scanning line direction to provide production capacity and yield.
In the shift register in each stage in an N-type bidirectional scanning GOA circuit, one terminal of the capacitor of the pull-up node is usually coupled to a low potential, so that in the period of outputting a gate signal, the bootstrap function of the capacitor becomes invalid, so that the potential of the pull-up node cannot ensure that the output transistor can be fully turned on. For example, the threshold voltage of the output transistor drifts in the high and low temperature reliability testing process. In such a case, the potential of the pull-up node cannot be maintained high, causing the output of the gate driving signal to be abnormal, thereby causing the display operation of the display panel to be defective or abnormal.